I'm wondering if anyone knows what type of paint/coating GM put on the inside of steel wheels. I recently took some tires off a set of rally wheels that have been sitting around for 30+ years. The inside of the wheels for the most part look OK, just a few surface rust spots. I want to sand blast the wheels, but need to know what this material is. It's like a rubber based black paint, almost tacky. There is some silver overspray. These wheels have been in my possession since new,and only one change of rubber.
Gary

The wheels have a black oxide finish and a black paint finish over that. Then they are painted Argent Silver. That black tacky stuff is probably dealer applied undercoating that was oversprayed into the rear of the wheel.

Big Dave

Thanks for the information Big Dave, I knew the wheels are sprayed/dipped in black oxide. But my concern is about the black tacky stuff inside the wheel, its not on the backside of the wheel. These wheels came off a Corvette,the owner drove the car a total of 4 blocks to the shop I managed. He wanted Crager mags w/Goodyear tires. I adjusted the price with the "Trade-in" of the Rallys and General tires. When my 70 Impala needed tires I put these on. I was thinking it was some kind of sealant that Chevrolet might of put in to help keep the tires on the rims for the "novice" Corvette owner. Later one other set of tires went on these rims, I thought maybe the Firestone dealer used something other than soap mounting the tires, but it (the tacky stuff) is spread evenly across the rims, and it's not on the inside of the tires that came off.
Gary